But they seem to know only recent events between the two countries, so I recommend to read this article written in 107 years ago.
"Japan's Task in Korea" North China Herald, 5 may 1905

(You can read the copy on P517; http://books.google.com/books?id=uRNDAQAAIAAJ&dq)
Koreans were already Japan haters before being occupied by Japan.
The reason was not anything like history or territory dispute but simply racism caused by Confucianism.
That is the core of Korea's Anti-Japan, they won't change, they won't understand criticism from outside.

PR

http://ninjer.blog.shinobi.jp/korea%20issue/korea-s%20anti-japan%20is%20not%20Korea's Anti-Japan is not history issue but traditional culture